This type of hydraulic damper is described, for example, in JP2004-532957 A. In the hydraulic damper described in JP2004-532957 A, an elastic wall member which is elastically deformed according to discharge pulsation (a hydraulic pressure variation on a high-pressure side) of a hydraulic pump is formed by two members, i.e., a plate-shaped sheet (diaphragm) made of spring steel and a rubber body for supporting the diaphragm.
In the hydraulic damper mentioned above, an outer periphery of the diaphragm is supported by the body, and when the diaphragm is elastically deformed according to the discharge pulsation (the hydraulic pressure variation on the high-pressure side) of the hydraulic pump, the outer periphery of the diaphragm scrapes against the body along with the elastic deformation of the diaphragm. Therefore, a hysteresis loss due to friction is large and it is difficult to obtain great hydraulic pressure variation absorbing effect (damper effect) with a small volume.